Disposable infusion device with tactile dosage volume indicator

ABSTRACT

A wearable infusion device comprises a reservoir that holds a liquid medicament, an outlet port that delivers the liquid medicament to a patient, a pump that delivers a volume of the liquid medicament from the reservoir to the outlet when actuated, and a tactile indicator representing the volume of the liquid medicament delivered to the outlet with each actuation of the pump.

BACKGROUND OF THE INVENTION

The present invention relates to infusion devices and more particularlyto such devices that enable liquid medicaments to be conveniently andsafely self-administered by a patient.

Tight control over the delivery of insulin in both type I diabetes(usually juvenile onset) and type II diabetes (usually late adultonset), has been shown to improve the quality of life as well as thegeneral health of these patients. Insulin delivery has been dominated bysubcutaneous injections of both long acting insulin to cover the basalneeds of the patient and by short acting insulin to compensate for mealsand snacks. Recently, the development of electronic, external insulininfusion pumps has allowed the continuous infusion of fast actinginsulin for the maintenance of the basal needs as well as thecompensatory doses (boluses) for meals and snacks. These infusionsystems have shown to improve control of blood glucose levels. However,they suffer the drawbacks of size, cost, and complexity. For example,these pumps are electronically controlled and must be programmed tosupply the desired amounts of basal and bolus insulin. This preventsmany patients from accepting this technology over the standardsubcutaneous injections.

Hence, there is a need in the art for a convenient form of insulintreatment which does not require significant programming or technicalskills to implement to service both basal and bolus needs. Preferably,such a treatment would be carried out by an infusion device that issimple to use and mechanically driven negating the need for batteriesand the like. It would also be preferable if the infusion device couldbe directly attached to the body and not require any electronics toprogram the delivery rates. The insulin is preferably delivered througha small, thin-walled tubing (cannula) through the skin into thesubcutaneous tissue similar to technologies in the prior art.

While the idea of such a simple insulin delivery device is compelling,many obstacles must be overcome before such a device may become apractical realty. One problem resides in insulin supply. Patients varygreatly on the amount of insulin such a device must carry to providetreatment over a fixed time period of, for example, three days. This isone environment where one size does not fit all. Still further, suchdevices must be wearable with safety and not subject to possibleaccidental dosing. Still further, such devices must be capable ofdelivering an accurately controlled volume of medicament withreliability. While it is preferred that these devices include all of theforgoing features, it would be further preferred if the cost ofmanufacturing such a device would be economical enough so as to renderthe device disposable after use. As will be seen subsequently, thedevices and methods described herein address these and other issues.

SUMMARY OF THE INVENTION

In one embodiment, a wearable infusion device comprises a reservoir thatholds a liquid medicament, an outlet port that delivers the liquidmedicament to a patient, a pump that delivers a volume of the liquidmedicament from the reservoir to the outlet when actuated, and a tactileindicator representing the volume of the liquid medicament delivered tothe outlet with each actuation of the pump.

The tactile indicator is configured to represent the volume in dosageunits. The tactile feature may comprise at least one relieved feature.The tactile feature may comprise at least one raised feature. The atleast one raised feature may comprise a bump. The tactile indicator maycomprise at least one discrete tactile feature. Each discrete tactilefeature may correspond to one dosage unit.

The device may further comprise an actuator button that, when pushed,actuates the pump. The tactile indicator may be carried on the actuatorbutton. The tactile indicator may be configured to represent the volumein dosage units. The tactile indicator may comprise at least onediscrete tactile feature with each discrete tactile featurecorresponding to one dosage unit.

The tactile indicator may comprise at least one relieved feature. Thetactile indicator may comprise at least one raised feature. The at leastone raised feature comprises a bump.

In another embodiment, the device may further comprise a pair ofactuator buttons associated with the pump which, when concurrentlypressed, cause the pump to be actuated. The tactile indicator may becarried on at least one of the actuator buttons.

The tactile indicator may be configured to represent the volume indosage units. The tactile indicator may comprise at least one discretetactile feature and each discrete tactile feature may correspond to onedosage unit.

The tactile indicator may comprise at least one relieved feature.Alternatively the tactile indicator may comprise at least one raisedfeature. The at least one raised feature may comprise a bump.

In another embodiment, a wearable infusion device comprises a reservoirthat holds a liquid medicament, an outlet port that delivers the liquidmedicament to a patient, a pump that delivers a volume of the liquidmedicament from the reservoir to the outlet when actuated, a tactileindicator representing the volume of the liquid medicament delivered tothe outlet with each actuation of the pump, and a pair of actuatorbuttons associated with the pump which, when concurrently pressed, causethe pump to be actuated. The tactile indicator may be carried on one ofthe actuator buttons.

One of the actuator buttons may be directly coupled to the pump. Thetactile indicator may be carried on the actuator button directly coupledto the pump. The pump may be a piston pump. The piston pump may includean extension, and the tactile indicator may be carried on the extension.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention which are believed to be novel areset forth with particularity in the appended claims. The invention,together with further features and advantages thereof, may best beunderstood by making reference to the following description taken inconjunction with the accompanying drawings, in the several figures ofwhich like reference numerals identify identical elements, and wherein:

FIG. 1 is a perspective view of a first infusion device embodyingcertain aspects of the present invention;

FIG. 2 is a schematic representation of the valves and pump of thedevice of FIG. 1;

FIG. 3 is an exploded perspective view of the device of FIG. 1;

FIG. 4 is a sectional view, in perspective, of the device of FIG. 1showing the pump of the device directly coupled to an actuator button;

FIG. 5 is a sectional view, in perspective, of the device of FIG. 1showing the valves and the valve and actuation linkages prior to thedelivery of a medicament dose;

FIG. 6 is a sectional view, to an enlarged scale, illustrating theactuation linkages prior to the delivery of a medicament dose;

FIG. 7 is a sectional view, like that of FIG. 6, illustrating theactuation linkages during the delivery of a medicament dose;

FIG. 8 is a another sectional view, like that of FIG. 5, illustratingthe actuation linkages just after the delivery of a medicament dose;

FIG. 9 is a perspective view of another infusion device embodyingvarious aspects of the present invention;

FIG. 10 is a schematic representation of the valves and pump of thedevice of FIG. 9 between medicament dosage delivery and for filling thepump with the medicament;

FIG. 11 is a schematic representation of the valves and pump of thedevice of FIG. 9 during medicament dosage delivery;

FIG. 12 is an exploded perspective view of the device of FIG. 9;

FIG. 13 is a perspective view of one component of the device of FIG. 9;

FIG. 14 is a lengthwise sectional view in perspective of the device ofFIG. 9 and showing a cannula assembly for use therein in exploded view;

FIG. 15 is a lengthwise sectional view in perspective of the device ofFIG. 9 similar to FIG. 14 showing the cannula assembly in operativeassociation with the device;

FIG. 16 is a sectional plan view showing the valve configuration of thedevice of FIG. 9 during pump filling;

FIG. 17 is a sectional plan view showing the valve configuration of thedevice of FIG. 9 during medicament delivery;

FIG. 18 is a sectional view, in perspective, to an enlarged scale,showing the actuation linkages of the device of FIG. 9 prior tomedicament dosage delivery;

FIG. 19 is a sectional view like that of FIG. 18, showing the actuationlinkages of the device of FIG. 9 during medicament dosage delivery;

FIG. 20 is a sectional view like that of FIG. 18, showing the actuationlinkages of the device of FIG. 9 after medicament dosage delivery;

FIG. 21 is a another sectional view, in perspective, to an enlargedscale, showing the operation of the actuation linkages;

FIG. 22 is another sectional view like that of FIG. 21, in perspective,to an enlarged scale, showing the operation of the actuation linkages;

FIG. 23 is still another sectional view showing the last dose lock-outand the device pump during normal medicament delivery actuation;

FIG. 24 is a sectional view, like that of FIG. 23, showing the last doselock-out and device pump after normal medicament delivery;

FIG. 25 is a sectional view, like that of FIG. 23, showing the last doselock-out being conditioned for disabling the actuator upon return of thedevice pump after a last normal medicament delivery;

FIG. 26 is a sectional view, like that of FIG. 23, showing the last doselock-out disabling the actuator upon a final medicament delivery;

FIG. 27 is another sectional view, to an enlarged scale, showing thedevice pump and the fill port being blocked during actuation fordelivery of medicament; and

FIG. 28 is another sectional view, like that of FIG. 22, showing thedevice pump and the fill port being locked in a blocked condition by thelast dose lock-out.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1 it is a perspective view of a first infusiondevice embodying certain aspects of the present invention. The device 10generally includes an enclosure 12, a base 14, a first actuator controlbutton 16, and a second actuator control button 18.

The enclosure 12, as will be seen subsequently, is formed by virtue ofmultiple device layers being brought together. Each layer definesvarious components of the device such as, for example, a reservoir,fluid conduits, pump chambers, and valve chambers, for example. Thisform of device construction, in accordance with aspects of the presentinvention, enables manufacturing economy to an extent rendering thedevice disposable after use.

The base 14 preferably includes an adhesive coating to permit the deviceto be adhered to a patient's skin. The adhesive coating may originallybe covered with a releasable cover that may be pealed off of the base 14when the patient endeavors to deploy the device 10. Such arrangementsare well known in the art.

The device 10 may be mated with a previously deployed cannula assembly.However, it is contemplated herein that the various aspects of thepresent invention may be realized within a device that may bealternatively first adhered to the patient's skin followed by thedeployment of a cannula thereafter.

The actuator buttons 16 and 18 are placed on opposites sides of thedevice 10 and directly across from each other. This renders moreconvenient the concurrent depression of the buttons when the patientwishes to receive a dose of the liquid medicament contained within thedevice 10. This arrangement also imposes substantially equal andopposite forces on the device during dosage delivery to prevent thedevice from being displaced and possibly stripped from the patient. Aswill be further seen hereinafter, the concurrent depression of thebuttons is used to particular advantage. More specifically, the actuatorbutton 16 may serve as a valve control which, when in a first positionas shown, establishes a first fluid path between the device reservoirand the device pump to support pump filling, and then, when in a secondor depressed position, establishes a second fluid path between thedevice pump and the device outlet or cannula to permit dosage deliveryto the patient. As will be further seen, a linkage between the controlactuator buttons 16 and 18 permits actuation of the device pump with theactuator control button 18 only when the second fluid path has beenestablished by the first actuator control button 16. Hence, the firstactuator control button 16 may be considered a safety control.

Referring now to FIG. 2, it is a schematic representation of the valvesand pump of the device 10 of FIG. 1. As may be seen in FIG. 2, thedevice 10 further includes a fill port 20, a reservoir 22, a pump 24,and the cannula 30. The device further includes a first valve 32 and asecond valve 34. Fluid conduit 40 provides a fluid connection betweenthe fill port 20 and the reservoir 22, fluid conduit 42 provides a fluidconnection between the reservoir 22 and the first valve 32, fluidconduit 44 provides a fluid connection between the first valve 32 andthe pump 24, fluid conduit 46 provides a fluid connection between thepump 24 and the second valve 34, and fluid conduit 48 provides a fluidconnection between the second valve 34 and the device outlet 50. Theoutlet 50 is arranged to communicate with the cannula 30.

It may also be noted that the actuator buttons 16 and 18 are springloaded by springs 36 and 38. The springs are provided for returning theactuator buttons to the first position after a dosage is administered.

The pump 24 of the device 10 comprises a piston pump. The pump 24includes a pump piston 26 and a pump chamber 28. In accordance with thisembodiment, the actuator control button 18 is directly coupled to and isan extension of the pump piston 26.

With further reference to FIG. 2, the device additionally includes afirst linkage 52 and a second linkage 54. The first linkage is a togglelinkage between the first valve 32 and the second valve 34. It isarranged to assure that the second valve 34 does not open until afterthe first valve 32 is closed. The second linkage 54 is between the firstactuator button 16 and the second actuator button 18. It is arranged toassure that the pump does not pump until after the first valve is closedand the second valve is opened by the first actuator button 16.

Still further, the second valve 34 is a safety valve that closes tighterresponsive to increased fluid pressure within fluid conduit 46. Thisassures that the liquid medicament is not accidentally administered tothe patient notwithstanding the inadvertent application of pressure tothe reservoir, for example. In applications such as this, it is notuncommon for the reservoir to be formed of flexible material. While thishas its advantages, it does present the risk that the reservoir may beaccidentally squeezed as it is worn. Because the second valve onlycloses tighter under such conditions, it is assured that increasedaccidental reservoir pressure will not cause the fluid medicament toflow to the cannula.

In operation, the reservoir is first filled through the fill port 20 toa desired level of medicament. In this state, the valves 32 and 34 willbe as shown. The first valve 32 will be open and the second valve 34will be closed. This permits the piston chamber 28 to be filled afterthe reservoir is filled. The cannula 30 may then be deployed followed bythe deployment of the device 10. In this state, the valves 32 and 34will still be as shown. The first valve 32 will be open and the secondvalve 34 will be closed. This permits the pump chamber 28 to be filledthrough a first fluid path including conduits 42 and 44 as the piston 24returns to its first position after each applied dose.

When the patient wishes to receive a dose of medicament, the actuatorbuttons are concurrently pressed. In accordance with aspects of thepresent invention, the linkage 52 causes the first valve 32 to close andthe second valve 34 to thereafter open. Meanwhile, the second linkage 54precludes actuation of the pump 24 until the first valve 32 is closedand the second valve 34 is opened by the first actuator button 16. Atthis point a second fluid path is established from the pump 24 to thecannula 30 through fluid conduits 46 and 48 and the outlet 50. Themedicament is then administered to the patient through cannula 30.

Once the medication dosage is administered, the piston 24, and thus theactuator button 18, is returned under the spring pressure of spring 38to its initial position. During the travel of the piston back to itsfirst position, a given volume of the liquid medicament for the nextdosage delivery is drawn from the reservoir into the pump chamber 28 toready the device for its next dosage delivery.

Referring now to FIG. 3, it is an exploded perspective view of thedevice of FIG. 1. It shows the various component parts of the device.The main component parts include the aforementioned device layersincluding the base layer 60, the reservoir membrane or intermediatelayer 62, and the top body layer 64. The base layer is a substantiallyrigid unitary structure that defines a first reservoir portion 66, thepump chamber 28, and valve sockets 68 and 70 of the first and secondvalves respectively. The base layer 60 may be formed of plastic, forexample. The reservoir membrane layer 62 is received over the reservoirportion 66 to form the reservoir 22 (FIG. 2). A valve seat structure 72is received over the valve sockets 68 and 70 to form the first andsecond valves 32 and 34 (FIG. 2) respectively. A rocker 74 is placedover the valves seat structure 72 to open and close the valves as willbe seen subsequently. The pump actuator button 18 carries the pumppiston that is received within the pump chamber 28. The pump actuatorbutton 18 also carries a cam cylinder 76 with a lock tube 78 thereinthat form a portion of the second linkage 54 (FIG. 2). The spring 38returns the actuator button 18 to its first position after each dosagedelivery.

The first actuator control button carries a valve timing cam 80 thatrocks the rocker 72. The button 16 further carries a cam cylinder 82 anda cam pin 84 that is received into the cam cylinder 82. The spring 36returns the actuator button 16 to its first position after each dosagedelivery. The top body layer 64 forms the top portion of the deviceenclosure. It receives a planar cap 86 that completes fluid paths 85partially formed in the top layer 64. Lastly, a needle 88 is providedthat provides fluid coupling from the cannula (not shown) to the outletof the device 10.

FIG. 4 shows a sectional view, in perspective, of the device of FIG. 1.More specifically, the figure shows details of the piston pump 24 withinthe device 10. Here, it may be seen that the piston 26 of the pistonpump 24 is received within the pump chamber 28 that is formed in thebase layer 60 of the device. The piston 26 may further be seen to be anextension of the actuator button 18. An O-ring 90 provides a sealbetween the pump chamber 28 and the piston 26. The spring 38 returns theactuator button 18 to its shown first position after each dosagedelivery.

FIG. 5 is a sectional view, in perspective, of the device of FIG. 1showing the valves 32 and 34 and the valve and actuation linkages priorto the delivery of a medicament dose. The valves will first bedescribed. First, it may be noted that the valve seat structure 72 isreceived within the valve sockets 68 and 70. The valve seat structure 72includes valve seats 92 and 94 that are received within the valvesockets 68 and 70 respectively. Each of the seats 92 and 94 has awidened portion 96 and 98, respectively, that cause the seats to be moretightly seated within sockets 68 and 70 in response to increased fluidpressure in the downward direction. As previously described, thisprotects against the potential effects of accidental medication deliverydue to external pressure being applied to the reservoir of the device.

The rocker 74 opens and closes the valves 32 and 34. It is under controlof the timing cam 80 carried by the first actuator control button 16. Asthe control button 16 is moved laterally, the cam 80 causes the rocker74 to pivot and to apply pressure to one or the other of the valve seats92 or 94. The shape of the cam surfaces on the rocker 74 and the cam 80assure that the valve 34 will not open until the valve 32 closes. Thecam 80 and rocker 74 thus form the first linkage 52 shown in FIG. 2.

While the cam 80 and rocker 74 are operating the valves 32 and 34 undertiming control provided by the first linkage 52, the second linkage 54is controlling when the pump may displace liquid medicament form thepump chamber 28 to the device outlet and cannula. FIGS. 5-8 show detailsof the second linkage.

As may be seen in FIGS. 5 and 6, the second linkage includes the camcylinder 76, the lock tube 78, the outer cam cylinder 82, and the campin 84. The cam cylinder is integral with the second actuator controlbutton 18 and the outer cam cylinder 82 is integral with the firstactuator control button. The second linkage 54 further includes a lockcylinder 100. The foregoing are disposed in a bore 102 formed in thebase layer 60 of the device.

When the actuator buttons are in their first position as shown in FIG.6, the end of the lock tube 78 abuts the end of the lock cylinder 100.The lock cylinder includes ears 104. When a dosage delivery is desired,the concurrent pushing of the buttons 16 and 18 causes the outer camcylinder 82 to slide over the lock cylinder 100 first and then the camcylinder 76 to slide over the lock tube 78. The sliding of the outer camcylinder 82 over the lock cylinder 100 causes the first valve to closeand the second valve to open. When this is accomplished, the camcylinder 76 is then permitted to slide over lock tube 78 to cause thepiston 26 to move through the pump chamber 28. This displaces the liquidmedicament in the pump chamber 28 for delivering the medicament to thecannula 30 and the patient.

FIG. 7 illustrates the manner in which the outer cam cylinder 82 slidesalong the lock cylinder 100. It may first be noted that the cam pin 84has a reduced diameter portion creating an annular space 106 between thepin 84 and the lock cylinder 100. The outer cam cylinder 82 engages thepin at a flange 108 of the pin 84. This engagement will cause the pin 84to move with the outer cam cylinder 82. The pushing of the firstactuator button 16 will cause the outer cam cylinder 82 to engage theears 104 of the lock cylinder 100 while at the same time, the end of thepin 84 moves into the lock tube 78. Eventually, the ears 104 aredepressed enough by the outer cam cylinder 82 as the end of the pin 84clears the end of the depressed lock cylinder 100 to permit the ears 104to enter space 106. This occurs with a snap sound and feel as it occurssuddenly. The outer cam cylinder 82 is now free to slide its completetravel distance over the lock cylinder 100. The valve 32 has now beenclosed and the valve 34 has been opened.

The snap action of the actuator buttons 16 and 18 provides positiveassurance to the patient that a dosage of medicament was delivered.Also, because the snap action only occurs when the pump actuator button18 completes it full travel, the patient will also know that a fulldosage was delivered.

After the outer cam cylinder 82 has completed its travel over the lockcylinder 100, the ears 104 will be displaced sufficiently into space 106to permit the cam cylinder 76 to clear the end of the lock cylinder 100and slide over the lock tube 78. The condition of the second linkage 54at this time is shown in FIG. 8. As previously described, as the camcylinder 76 slides over the lock tube 78, the pump 24 is actuated todeliver the medicament to the patient.

Referring now to FIG. 9, it is a perspective view of another infusiondevice embodying various aspects of the present invention. The device210 generally includes an enclosure 212, a base 214, a first actuatorcontrol button 216, and a second actuator control button 218.

The enclosure 212 is formed by virtue of multiple device layers beingbrought together. Each layer defines various components of the devicesuch as, for example, a reservoir, fluid conduits, pumps, and valvechambers, for example. This form of device construction, in accordancewith aspects of the present invention, enables manufacturing economy toan extent rendering the device disposable after use.

The base 214 preferably includes an adhesive coating to permit thedevice to be adhered to a patient's skin. The adhesive coating mayoriginally be covered with a releasable cover that may be pealed off ofthe base 214 when the patient endeavors to deploy the device 210. Sucharrangements are well known in the art.

As will also be seen subsequently, the device 210 may be mated with apreviously deployed cannula assembly. However, it is contemplated hereinthat the various aspects of the present invention may be realized withina device that may be alternatively first adhered to the patient's skinfollowed by the deployment of a cannula thereafter.

As in the previous embodiment, the actuator buttons 216 and 218 areplaced on opposites sides of the device 210 and directly across fromeach other. This again renders more convenient the concurrent depressionof the buttons when the patient wishes to receive a dose of the liquidmedicament contained within the device 210. This arrangement alsoimposes substantially equal and opposite forces on the device duringdosage delivery to prevent the device from being displaced and possiblystripped from the patient. As will be further seen hereinafter, theconcurrent depression of the buttons is used to particular advantage.More specifically, the actuator button 216 may serve as a valve controlwhich, when in a first position as shown, establishes a first fluid pathbetween the device reservoir and the device pump to support pumpfilling, and then, when in a second or depressed position, establishes asecond fluid path between the device pump and the device outlet orcannula to permit dosage delivery to the patient. As will be furtherseen, a linkage between the control actuator buttons 216 and 218 permitsactuation of the device pump with the actuator control button 218 onlywhen the second fluid path has been established by the first actuatorcontrol button 216. Hence, the first actuator control button 216 may beconsidered a safety control.

With continued reference to FIG. 9, it may be further noted that thedevice 210 also includes a tactile indicator 260 that represents thevolume of the liquid medicament delivered by the device with eachactuation of the pump 224. The tactile indicator is carried by the pumpactuator button 218 and takes the form of a plurality of distinct raisedfeatures or bumps 262 and 264. Alternatively, the tactile indicator maytake the form of one or more distinct relieved portions. Each bump 262and 264 may correspond to a single unit of medicament. Hence, in thisembodiment, the bumps 262 and 264 indicate that the device delivers twounits of medicament with each actuation of the pump.

The tactile indicator 260 being carried on the pump actuator controlbutton 218 provides a very significant feature and advantage. As will beseen subsequently, the pump actuator button 218 has an integralextension that forms the piston 226 of the piston pump 224 asrepresented in FIG. 10 to be described hereinafter. It will also be seenthat the piston chamber 228 is formed in a component of the device thatmay be used in devices delivering dosage amounts other than two units.The component may be common to all such devices because it would have afixed piston chamber length and the dosage amount is determined by thethrow of the pump piston 226. Each piston throw is integral to the partand corresponds to a respective given dosage amount. Each pump actuatorbutton for a given dosage amount may have then be provided with acorresponding tactile indicator. Hence, if a tactile indicator indicatesa dosage amount of two units, for example, it is assured that that isthe medicament amount delivered with that particular pump button.Further, this arrangement is advantageous from a manufacturingstandpoint because the actuator buttons for the various dosage sizedevices cannot be confused with each other.

Referring now to FIGS. 10 and 11, they are schematic representations ofthe valves and pump of the device of FIG. 9 between medicament dosagefilling (FIG. 10) and medicament dosage delivery (FIG. 11) As may beseen in FIGS. 10 and 11, the device 210 further includes a reservoir222, a pump 224, and the cannula 230. The device further includes ashuttle valve 231 forming a first valve 232 defined by O-rings 233 and235 and a second valve 234 defined by O-rings 237 and 239. AlthoughO-rings are used herein to form seals, other types of valve constructionmay best employ forms of seals other than O-rings without departing fromthe invention. Fluid conduit 240 extends between the valves 232 and 234.A fluid conduit 242 provides a fluid connection between the reservoir222 and the shuttle valve 231 and fluid conduit 244 provides a fluidconnection between the shuttle valve 231 and the pump 224. A furtherfluid conduit 246 provides a fluid connection between the shuttle valve231 and the device outlet 250. The outlet 250, in the form of a needle,is arranged to communicate with the cannula 230.

It may also be noted that the actuator buttons 216 and 218 are springloaded by springs 236 and 238. The springs are provided for returningthe actuator buttons to the first position after a dosage isadministered.

The pump 224 of the device 210 comprises a piston pump. The pump 224includes a pump piston 226 and a pump chamber 228. In accordance withthis embodiment, the actuator control button 218 is directly coupled toand is an extension of the pump piston 226.

With further reference to FIGS. 10 and 11, the device additionallyincludes a first linkage 252 and a second linkage 254. The first linkageis formed by the shuttle bar 241 of the first valve 232 and the secondvalve 234. It is arranged by separating the valves 232 and 234 be adistance that assures that the second valve 234 does not open untilafter the first valve 232 is closed. The second linkage 254 is betweenthe first actuator button 216 and the second actuator button 218. It isarranged to assure that the pump 224 does not pump until after the firstvalve 232 is closed and the second valve 234 is opened by the firstactuator button 216.

Still further, the second valve 234 is a safety valve that assures thatthe liquid medicament is not accidentally administered to the patientnotwithstanding the inadvertent application of pressure to thereservoir, for example. In applications such as this, it is not uncommonfor the reservoir to be formed of flexible material. While this has itsadvantages, it does present the risk that the reservoir may beaccidentally squeezed as it is worn. Because of the second valve 234, itis assured that accidental reservoir pressure will not cause the fluidmedicament to flow to the cannula.

In operation, the pump chamber 228 is first filled as the actuatorbutton 218 returns to the first position after having just delivered amedicament dosage. In this state, the shuttle valve 231 is set so thatthe first valve 232 will be open (the reservoir 222 communicates withthe fluid conduit 240) and the second valve 234 will be closed (theconduit 246 is closed off from fluid conduit 240). This establishes afirst fluid path from the reservoir 222 to the pump 224 through conduits242, 240 and 244 that permits the piston chamber 228 to be filled by thereservoir as the actuator button is returned to its first position underthe influence of the spring 238.

When the patient wishes to receive another dose of medicament, theactuator buttons are concurrently pressed. In accordance with aspects ofthe present invention, the linkage 252 causes the first valve 232 toclose and the second valve 234 to thereafter open. Meanwhile, the secondlinkage 254 precludes actuation of the pump 224 until the first valve332 is closed and the second valve 334 is opened by the first actuatorbutton 216. At this point a second fluid path is established from thepump 224 to the cannula 30 through fluid conduits 244, 240 and 246 andthe outlet 250. The medicament is then administered to the patientthrough cannula 30.

Once the medication dosage is administered, the piston 224, and thus theactuator button 218, is returned under the spring pressure of spring 238to its initial position. During the travel of the piston back to itsfirst position, a given volume of the liquid medicament for the nextdosage delivery is drawn from the reservoir into the pump chamber 228 asdescribed above to ready the device for its next dosage delivery.

Referring now to FIG. 12, it is an exploded perspective view of thedevice of FIG. 9. It shows the various component parts of the device210. Like the device 10 of FIG. 1, the device 210 is constructed indevice layers including a base layer 280, an intermediate layer 282, andthe top body layer 284.

As may also be seen in FIG. 13, the base layer 280 is a substantiallyrigid unitary structure that defines a first reservoir portion 286, thepump chamber 228, and a valve chamber 290 for the first and secondvalves 232 and 234. The base layer 280 may be formed of plastic, forexample.

The valve chamber 290 is arranged to receive the valve shuttle bar 241carried by and extending from the first actuator button 216. O-rings233, 235, 237, and 239 are arranged to be seated on the shuttle bar 241to form the first and second valves 232 and 234 respectively (FIG. 10).The actuator button 216 also carries a first portion 292 of the secondlinkage 254 (FIG. 10). The second linkage is received within a suitablyconfigured bore 295 formed in the base layer 280 and will be describedsubsequently.

The pump actuator button 218 carries the pump piston 226 and a secondportion 294 of the second linkage 254. The pump piston 226 is arrangedto be received within the pump chamber 228 and the second portion 294 ofthe second linkage 254 is arranged to be received within the bore 295for interacting with the first portion 292. O-rings 300 and 302 arearranged to be seated on the piston 226 to provide a seal againstleakage and to prevent external contaminants from entering the pistonchamber. The base layer 280 further includes fluid channels 304 thatserve to form the fluid conduits illustrated in FIG. 10. Finally,springs 306 and 308 are arranged to spring load the actuator buttons 216and 218.

The intermediate layer 282 is formed of flexible membrane material. Aportion 296 of the intermediate layer is received over the reservoirportion 286 to form the reservoir 222 (FIG. 10). A rigid plate 310 isarranged to be adhered to the portion 296 of the reservoir. Because thelayer 282 is flexible membrane, it will move as the reservoir is filledand emptied. The rigid plate 310 will then move with it. The plateincludes an eyelet 312 dimensioned to receive an elongated web 314 thatforms a part of a medicament level indicator to be describedhereinafter. The web 314 carries an indicator line or feature 316.

The top layer 284 is arranged to be received over the intermediate layer282 and adhered to the base layer. It includes a panel 320 having a viewwindow 318 through which the medicament level indicator line may beobserved.

Lastly with respect to FIG. 12, it may be noted the device 210 furtherincludes a pin 322. The pin 322 is a locking pin that is employed tolock the actuator buttons after a last medicament dose is delivered. Italso serves to maintain the device fill port, to be describedsubsequently, in a blocked condition after a last medicament dose isdelivered.

Referring now to FIGS. 14 and 15, they are lengthwise sectional views,in perspective, of the device of FIG. 9 along with a cannula assemblythat may be deployed in the device. FIG. 14 illustrates the previouslydescribed layered structure of the device 210 including device layers280, 282, and 284. As may also be noted in FIG. 14, the device includesa port for receiving a cannula assembly 340. The cannula assembly has abase 342, a generally cylindrical docking structure 344, and a cannula346. The docking structure 344 is arranged to be received by the port330 (FIG. 15) after the cannula assembly 340 is applied to the patient'sskin with the cannula projecting beneath the patient's skin. The deviceincludes a needle 348 that projects through a septum 350 of the devicewhen the cannula assembly 340 is received by the port 330. Thiscompletes the fluid path from the reservoir 222 to the cannula 346. Fora more detailed description of such a cannula assembly and the devicethat utilizes the same, reference may be had to co-pending U.S.application Ser. No. 11/803,007, filed May 11, 2007, and entitledINFUSION ASSEMBLY, which application is owned by the present assigneeand incorporated herein by reference.

FIGS. 14 and 15 also clearly illustrate a medicament level indicatorembodying the present invention. The rigid plate 310 forms a moveablewall that moves as the medicament volume increases and decreases withinthe reservoir. The elongated web 316 is preferably formed from anon-elastic, non-compressible, elongated material. It has a first end352 and a second end 354. The web is fixed at the first end 352 withrespect to the rigid plate 310 of the reservoir 222 and is arranged tomove in a first plane generally perpendicular to the rigid plate 310intermediate the first and second ends 352 and 354. Because the web 316is fixed at the first end 352 and free to move within the eyelet 312,its second end 354 will move in linear movement in a second planesubstantially parallel to the rigid member and transverse to the firstplane.

As previously mentioned, a panel 320 of the top layer 284 has a windowopening 318 to render the medicament level indicia viewable. The coverpanel 320 forms a guide channel 356 that receives and confines the websecond end to guide the web for linear movement in the second planesubstantially transverse to the first plane. As the reservoir is filledor emptied, a glance through the window 318 will provide an indicationof the level of the medicament in the reservoir 222.

Referring now to FIG. 16, it is a sectional plan view showing the valveconfiguration of the device 210 of FIG. 9 during medicament filling ofthe pump chamber 228 immediately after a dosage delivery. Here, it maybe clearly seen that the first actuator button 216 has an extensioncomprising the shuttle bar 241 of the valves 232 and 234. Above thevalves are the conduits from the reservoir, from the pump, and to thecannula. More particularly, the conduit 242 is in fluid communicationwith the reservoir 222 (FIG. 10), the conduit 244 is in fluidcommunication with the pump, and the conduit 246 is in fluidcommunication with the cannula. The valves are shown with the firstvalve 232 opened and not blocking the reservoir conduit 242, and thesecond valve 234 closed and blocking the conduit 246 to the cannula.This permits medicament to flow from the reservoir through conduit 242and to the pump chamber 228 through conduit 244 as the actuator button216 returns to its first position. Hence, the pump chamber is filled andready for the next dosage delivery.

Referring now to FIG. 17, it is a sectional plan view showing the valveconfiguration of the device 210 of FIG. 9 during medicament delivery.Here, the valves are shown with the first valve 232 closed and blockingthe reservoir conduit 242, and the second valve 234 open permittingmedicament to flow from the pump through conduit 244 and to the cannulathrough conduit 246. As previously mentioned, the first and secondvalves 232 and 234, respectively, are spaced apart so that conduit 242is blocked before conduit 246 is opened.

FIGS. 18-22 show details of the operation of the second linkage 254 ofthe device 210. Through this discussion, simultaneous reference to morethan one drawing figure may be necessary. As may be seen FIG. 18, thefirst actuator button 216 has an extension 380 that terminates in ablock 382 having a first ramp surface 384 and a second ramp surface 386.When the device 210 is actuated, the button 216 is concurrentlydepressed with pump button 218. It and its extension 380 and bloc 382are free to move to the right. As seen in FIGS. 18 and 21, the pumpactuator button 218 has parallel extensions 400 and 402 which are joinedand separated be a rod member 404. As seen in FIG. 18, the extension 400abuts an abutment 388 which it must clear to be able to move to theleft. As shown in FIG. 21, as the button 216 is depressed, its extension380 moves to the right causing the first ramp surface to engage the rodmember 404. Continued movement of the button causes the rod member 404to rise up under the first ramp surface 384 which in turn causes theextension 400 to begin to move slightly to the left and bend upwardabout rib 405. Eventually, the rod member 404 rides up the length of thefirst ramp 384 causing the end 401 of extension 400 to clear theabutment 388 as shown in FIG. 19. The pump button 216 is now able tomove freely to the left. When the end 401 of extension 400 totallyclears the abutment 388, it will snap behind the abutment 388 as shownin FIG. 20 and become temporarily locked. Meanwhile, as shown in FIG.22, the rod member 404 has traversed down the second ramp surface 386.The buttons 216 and 218 are now fully depressed.

Hence, from the above, it may be seen that the pump button 218 could notat first move freely while the first actuator button 216 which operatesthe valves could. As a result, the pump actuation lags behind the valveactuation causing the first valve 232 (FIG. 10) to be closed and thesecond valve 234 to be opened, establishing a medicament delivery flowpath to the cannula, before the pump is able to begin pumping themedicament to the patient. Because this operation occurs quickly, itappears to the patient that both actuator buttons are moving at the samerate.

When the extension 400 of the pump button clears the abutment 388, itbecomes locked in a snap action. As in the previous embodiment, thisprovides positive feedback to the patient that a dosage of medicamentwas delivered as desired. It also causes a full dose to be delivered. Byvirtue of the snap action of the pump actuator, only full doses may beadministered.

When the medicament has been delivered, the spring loading of theactuator buttons returns the buttons to their first or initial position.During this time, the same timing provided by the block 382 is used forrecharging the pump. More specifically, ramp 366 unlatches the end 401of extension 400 by lifting rod member 404 so that 246 is closed andconduit 242 is opened before the pump is returned by the spring to itsinitial position. This assures that the pump does not pull medicamentfrom the patient but only from the reservoir. As the piston 226 of thepiston pump 224 returns, a full dose of the medicament is drawn up intothe piston chamber 228 to ready the device for the next dosage delivery.

FIGS. 23 and 24 show the operation of the piston pump 224 in greaterdetail. Also shown is a last dose lock-out 420 that will be describedsubsequently. Here it may be seen that the piston 226 of pump 224 is anextension of the pump actuator button 218. Also, it may be seen that theO-rings 300 and 302 seal the piston 226 and the chamber 228. The doubleO-rings both prevent leakage of medicament from the camber 228 andprevent outside contaminants from entering the chamber 228.

When the pump chamber is filled with medicament as the actuator buttonis returned from the second position shown in FIG. 24 to the first orinitial position shown in FIG. 23 after a dosage delivery, medicamentflows from the reservoir, through a conduit 307 (FIG. 13), through adiaphragm chamber 424 and through the conduit 244 to the pump chamber228. The chamber 424 is defined by a diaphragm 422 formed of flexiblemembrane material. The diaphragm 422 includes an extension whichcaptures the pin 322, previously shown in the exploded view of FIG. 12.As long as the reservoir has medicament, and hence is not empty, thediaphragm 422 is not affected. In this state, the button 216 is free tobe actuated.

As may be noted, the pin is L-shaped at end 323 with an L-extension 428.A capture ramp 430, integral with the actuator button, passes adjacentto the pin 322 and over the L-extension 328. This occurs when theactuator button is depressed as long as the reservoir has sufficientmedicament to provide at least one more dosage delivery.

Reference may now be had to FIGS. 25 and 26 as the operation of the lastdose lock-out 420 is described. When the reservoir has insufficientmedicament to support delivery of another dose of medicament, and duringthe return of the actuator button 218 after what will be the last dosedelivered, a negative pressure is created in the diaphragm chamber 424.This causes the diaphragm 422 to be drawn into the chamber 424 due tothe absence of liquid medicament in the chamber 424. As the diaphragm422 is drawn into the chamber 424, the pin 322 is drawn upward with thediaphragm 422 where it engages an abutment 432 connected to the rampextension 430. The pin 322 is now caused to be captured between the ramp430 and the abutment 432. The button 216 is now only partially returnedto its first position whereas the pump actuator button 218 is free tofully return to its initial position. Upon the next attempted actuationof the device, the L-extension will ride up the ramp 430 and fall into alocked position between the ramp 430 and a shoulder 434 formed in theactuator button 216. The button is now locked and cannot be returned toits first position. The pump actuator button 218 will also be locked inits second position as shown in FIG. 26. This is due to the fact thatthe first button 216 is not able to return from its second positionwhich, as shown in FIG. 20, causes the end 401 of the extension 400 ofthe pump actuator 218 be locked between the abutment 388 and actuatorbutton 216. Hence, the device 210 is now locked and cannot be reused.

Referring now to FIGS. 27 and 28, they illustrate a further aspect ofthe last dose lock-out. Before the device 210 can be used to deliver amedicament, its reservoir must be filled with a medicament. To this end,the device 210 is provided with a fill port 440 that communicates withthe reservoir. When the device 210 is filled with medicament, theactuator buttons 216 and 218 are in their initial positions. The firstactuator button 216 further includes another extension 442 which doesnot cover the fill port 440 when the actuator button 216 is in itsinitial position. However, when the actuator button 216 is in its fullyactuated second position, it does block the fill port 440 as seen inFIG. 28. When the last dose lock-out has the locked the device, theactuator button 216 is left in its fully actuated second position. As aresult, the last dose lock-out not only locks both actuator buttons 216and 218 to disable the device 210, it also blocks the fill port 440 tofurther render the device disabled.

While particular embodiments of the present invention have been shownand described, modifications may be made. For example, instead of manualactuation and spring loaded return of the valves used herein,constructions are possible which perform in a reversed manner by beingspring actuated and manually returned. It is therefore intended in theappended claims to cover all such changes and modifications which fallwithin the true spirit and scope of the invention as defined by thoseclaims.

1. A wearable infusion device comprising: a base arranged to be adheredto a patient's skin; a reservoir that holds a liquid medicament and thathas a capacity; an outlet port that delivers the liquid medicament to apatient; a pump that delivers a volume of the liquid medicament from thereservoir to the outlet when actuated, the pump delivering, with eachactuation, a volume of medicament to the outlet that is less than thecapacity of the reservoir; and a tactile indicator representing thevolume of the liquid medicament delivered to the outlet with eachactuation of the pump, wherein the pump is a piston pump, wherein thepiston pump includes an extension, and wherein the tactile indicator iscarried on the extension.
 2. The device of claim 1, wherein the tactileindicator is configured to represent the volume in dosage units.
 3. Thedevice of claim 1, wherein the tactile feature comprises at least onerelieved feature.
 4. The device of claim 1, wherein the tactile featurecomprises at least one raised feature.
 5. The device of claim 4, whereinthe at least one raised feature comprises a bump.
 6. The device of claim1, wherein the tactile indicator comprises at least one discrete tactilefeature and wherein each discrete tactile feature corresponds to onedosage unit.
 7. The device of claim 1, further comprising an actuatorbutton that, when pushed, actuates the pump, and wherein the tactileindicator is carried on the actuator button.
 8. The device of claim 7,wherein the tactile indicator is configured to represent the volume indosage units.
 9. The device of claim 7, wherein the tactile indicatorcomprises at least one discrete tactile feature and wherein eachdiscrete tactile feature corresponds to one dosage unit.
 10. The deviceof claim 7, wherein the tactile indicator comprises at least onerelieved feature.
 11. The device of claim 7, wherein the tactileindicator comprises at least one raised feature.
 12. The device of claim11, wherein the at least one raised feature comprises a bump.
 13. Thedevice of claim 1, further comprising a pair of actuator buttonsassociated with the pump which, when concurrently pressed, cause thepump to be actuated, wherein the tactile indicator is carried on atleast one of the actuator buttons, and wherein the at least one of theactuator buttons is carried on the extension.
 14. The device of claim13, wherein the tactile indicator is configured to represent the volumein dosage units.
 15. The device of claim 13, wherein the tactileindicator comprises at least one discrete tactile feature and whereineach discrete tactile feature corresponds to one dosage unit.
 16. Thedevice of claim 13, wherein the tactile indicator comprises at least onerelieved feature.
 17. The device of claim 13, wherein the tactileindicator comprises at least one raised feature.
 18. The device of claim17, wherein the at least one raised feature comprises a bump.
 19. Awearable infusion device comprising: a base arranged to be adhered to apatient's skin; a reservoir that holds a liquid medicament and that hasa capacity; an outlet port that delivers the liquid medicament to apatient; a pump that delivers a volume of the liquid medicament from thereservoir to the outlet when actuated, the pump delivering, with eachactuation, a volume of medicament to the outlet that is less than thecapacity of the reservoir; a tactile indicator representing the volumeof the liquid medicament delivered to the outlet with each actuation ofthe pump; and a pair of actuator buttons associated with the pump which,when concurrently pressed, cause the pump to be actuated, wherein thetactile indicator is carried on one of the actuator buttons, wherein thepump is a piston pump, wherein the piston pump includes an extension,and wherein the tactile indicator is carried on the extension.
 20. Awearable infusion device comprising; a base arranged to be adhered to apatient's skin; a reservoir that holds a liquid medicament; an outletport that delivers the liquid medicament to a patient; a pump thatdelivers a volume of the liquid medicament from the reservoir to theoutlet when actuated; a tactile indicator representing the volume of theliquid medicament delivered to the outlet with each actuation of thepump; and a pair of actuator buttons associated with the pump which,when concurrently pressed, cause the pump to be actuated, wherein thetactile indicator is carried on one of the actuator buttons, wherein oneof the actuator buttons is directly coupled to the pump, wherein thetactile indicator is carried on the actuator button directly coupled tothe pump, wherein the pump is a piston pump, wherein the piston pumpincludes an extension, and wherein the tactile indicator is carried onthe extension.